JPH07214666A - Apparatus for mutually fusing and cutting multilayered films - Google Patents

Abstract

PURPOSE:To simultaneously perform the certain fusion sealing of multilayered films each composed of synthetic resin films different in characteristics by a seal bar and the efficient cutting thereof along a cutting line. CONSTITUTION:Even with respect to multilayered films having special characteristics markedly different in fusion temp., the front and rear fusion parts thereof are simultaneously fused by a single device and the intermediate parts of the fused parts are cut by the single operation of a cutting blade 45 having a sawtooth like edge 45a operated independently separated from a heating seal bar 43 and, therefore, the front and rear fusion seal parts are certainly sealed by the seal bar 43. At the same time, the cutting blade 45 does not become an overheated state because it receives no effect of the heating seal bar 43 and the intermediate cutting parts are accurately and efficiently cut without melting the films by the mere pressing operation of the cutting blade 45.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a welding / cutting apparatus for synthetic resin films, which is applied to automatic packaging machines and the like.

[0002]

2. Description of the Related Art A conventional plastic film fusing and welding apparatus disclosed in, for example, Japanese Utility Model Publication No. 5-6105 has a seal bar and a seal pedestal and accommodates articles to be packaged therein intermittently. A device for sequentially fusing and sealing the supplied two-fold film, having a cutting blade projecting a blade portion from a sealing surface of the seal bar in a width center portion of the seal bar, and the blade portion is sharp. The cutting edges are formed in a saw-tooth shape arranged at equal intervals, and a recessed groove of a size large enough for the cut blade to be loosely fitted is formed on the surface of the seal receiving base that faces the cut blade. Has been formed.

According to this device, the seal bar and the cutting blade are simultaneously lowered, and the saw blade edges of the cutting blade are provided before the sealing surfaces of the sealing bars on both sides of the cutting blade press the upper and lower films against the seal holder. Is pierced along the cutting line, and then the seal bar presses the upper and lower films against the surface of the seal pedestal for welding and sealing, and at the same time, cuts the upper and lower films along the cutting line by the cutting edge. At the time of this cutting, since the upper and lower films are tensioned toward the pair of seal bars, the saw blade-shaped blade edge is lowered so as to bite into the upper and lower films, whereby the upper and lower films are easily and reliably cut.

[0004]

By the way, recently, the film materials for packaging have been diversified, and the development of materials capable of meeting various requirements of articles to be packaged has been advanced. According to the above-mentioned plastic film fusing / welding device, when a multilayer film made of a thermoplastic synthetic resin film such as ordinary polyethylene, polyester, polyamide or the like is used alone or in combination thereof, there is no particular trouble and the intended purpose is achieved. Although it is possible to perform fusion welding along the same line, for example, a multi-layer film of a saponified ethylene vinyl acetate copolymer (EV0H) having a high fusion temperature and a low-density polyethylene having a low fusion temperature, or an ethylene of the same multi-layer film Thermoplastic synthetic resins having a large difference in fusion temperature such as a multilayer film having a metal film on the surface of a saponified vinyl acetate copolymer layer,
Alternatively, a multilayer film obtained by laminating a metal film which is a non-welding material and a synthetic resin laminated film does not often give expected results.

For example, a film made of a saponified product of the ethylene-vinyl acetate copolymer has been adopted to enhance the airtightness of a package, but since it has an extremely high melting point, it is heated by a conventional seal bar. In the range, reliable welding is difficult and there is a problem in the welding performance. Further, even if the seal bar can be heated to a high temperature, pinholes are likely to be generated in the saponified ethylene vinyl acetate copolymer, and further, the effect of the high temperature on the article to be packaged inside is inevitable, There are many difficulties in the sealing technology. Therefore, in order to eliminate the influence of high heat on the article to be packaged, and to improve the sealing performance as well as ensuring the airtightness of the package, a film made of the above-mentioned material, for example, a low-density polyethylene film or polypropylene film having a low melting point, etc. (Diffusion temperature difference, 120 ° C to 350 ° C) is laminated and integrated by laminating, and the multilayer film is encapsulated with the polyethylene film surface as the inner surface, and the upper and lower multilayer films are welded together for reliable sealing performance. Attempts have been made to obtain.

However, in this case, even in the case of a polyethylene film having a low melting point, the temperature of the seal bar needs to be raised up to its welding temperature through the film made of the saponified product of ethylene vinyl acetate copolymer. The surface must be set above normal temperature. Therefore, for example, if an attempt is made to simultaneously perform welding and fusing on the multilayer film using the above-mentioned conventional fusing and fusing apparatus for plastic films, it is necessary to raise the temperature of the seal bar above the melting temperature of polyethylene. Therefore, the cutting blade having the saw-toothed blade edge becomes almost the same temperature as the above temperature, and the polyethylene film having a low melting point is melted more than necessary, and conversely the sealing function cannot be achieved.

Accordingly, an object of the present invention is to provide a strong weld sealing performance by a seal bar and efficient cutting along a cutting line even in the case of a multi-layer film of synthetic resin films having a large difference in fusion temperature as described above. It is an object of the present invention to provide a fusion cutting and welding device for a multilayer film which can be obtained simultaneously.

[0008]

The above-mentioned object is provided with a heating seal bar and a seal cradle, which are the main components of the present invention, and the upper and lower parts 2 which accommodate articles to be packaged and are supplied intermittently. A multi-layer film welding / cutting device for sequentially welding and sealing a plurality of multi-layer films simultaneously, wherein the seal receiving table has a void portion sandwiching a cutting line of the multi-layer film, and each receiving surface runs the film. A cutting blade that is installed facing the surface, and that moves into and out of the cavity from the receiving surface to an upper position of a predetermined height by the first operating means,
The blade portion of the same cutting blade is in the shape of a saw blade in which sharp blade edges are arranged at equal intervals, and the seal bar has a groove for receiving the blade edge of the cut blade in the width center portion of its sealing surface. A second sealing surface that is arranged to face the receiving surfaces and that moves up and down between the receiving surface pressing position and the upper standby position.
A timing control means for operating the second operating means, the first operating means for operating the second operating means to press the respective receiving surfaces and then raising the cutting blade to the upper limit position. And a welding cutting device for a multilayer film.

According to a preferred embodiment, the multi-layer film comprises two or more synthetic resin film layers having different welding performances, or a multi-layer film having a metal film on the surface of the synthetic resin film layer. The seal bar and the cutting blade are substantially L-shaped, and each receiving surface of the seal receiving base is made of an elastic material made of a rubber material or the like.

[0010]

According to the above structure, the next packaged article transferred from the packaged article supply section is accommodated in the opening of the bifold film which is inverted at the film inversion opening and moves horizontally. When it reaches the welding cutting device, the pair of left and right heated seat bars waiting above the pair of left and right receiving surfaces of the seal receiving stand descends, and each sealing surface of the seal bar main body is moved to the upper side. The upstream opening and the side edge opening of the folded film are pressed against the receiving surface at the same time, and the low welding film of the multilayer film is welded and sealed. Then, the cutting blade between the left and right receiving surfaces moves up a predetermined stroke, and the saw blade-shaped blade edge cuts while piercing the middle of the upper and lower multilayer films stretched between the left and right sealing surfaces and the left and right receiving surfaces.

According to the present invention, in the case where the multilayer film has heat shrinkability, the bi-fold film between the seal surfaces is heated to a certain extent and heat-shrinks during welding by the seal surfaces. I am nervous. for that reason,
At the same time when the sharp cutting edge of the cutting blade is pierced, the cut edge is enlarged, and the bi-fold film is surely cut before the cutting blade rises up. Even if the multilayer film does not have heat shrinkage performance, according to the cutting structure of the present invention, the cutting blade 45 can be completely cut along the cutting edge row by only raising the cutting blade 45 to the end. .

When this cutting is completed, the cutting blade is lowered, the cutting edge is recessed between the left and right receiving surfaces, and then the seal bar together with the upper frame is raised to the standby position to complete the packaging. A package discharge part is arranged on the downstream side of the device of the present invention as in the conventional case, and a heat tunnel is installed in the middle of the package discharge part. The package in (1) passes through a heat tunnel while being transferred to the package discharge section and discharged, and the film is heat-shrinked in the tunnel and comes into close contact with the entire surface of the packaged article.

[0013]

EXAMPLE First, an example of the present invention will be specifically described centering on a double-folded film automatic packaging machine to which the multi-layer film welding cutting apparatus according to the present invention is applied. FIG. 1 is a perspective view showing the entire configuration of the packaging machine, FIG. 2 is an enlarged perspective view showing a main part of the welding cutting device according to the present invention by cutting out a part thereof, and FIG.
FIG. 6 is a sectional view of an essential part showing the configuration of the same welding cutting device, and FIG. 6 is a plan view showing a seal bar structure at a corner of a welding cutting device having an L-shaped structure which is a typical embodiment of the present invention. . In addition, the phantom line in FIG. 6 shows the cutting blade structure of the seal pedestal applied to the same apparatus.

Further, in the following examples, a film obtained by laminating a low density polyethylene film on a film made of a saponified ethylene vinyl acetate copolymer having heat shrinkability as described above is used as the multilayer film. The invention is not limited to the film, a multilayer film in which a metal film is formed on the surface of the saponified ethylene vinyl acetate copolymer layer of the film, or a normal thermoplastic resin such as polyethylene, polypropylene, polyester or polyamide. It can also be applied to a multilayer film made of synthetic resin.

1 to 3, reference numeral 1 is the automatic wrapping machine for double-folded film. The wrapping machine 1 includes a film supply section 10, a film reversing opening 20, a packaged article supply section 30, and the present invention. An L-shaped sealer 40 according to an example, a package discharge unit 50, and a heat tunnel (not shown) are provided.

The film supply unit 10 has a double-folded film.
A support roller 13 for horizontally supporting the roll film 11 in which 12 is wound around a paper tube or the like is installed on a machine frame (not shown), and the guide roller 14 is provided between the support roller 13 and the film reversing opening 20. It is provided on the machine frame. Roll film 11
The half-folded film 12 pulled out from the film reaches the film reversal opening 20 via the guide roller 14.

The film reversal opening 20 has a substantially right angle 3
Two rectangular plates 21,21 are one side 21-
With 1,21-1 as the bottom side and the other side 21-2, 21-2 sandwiching a right angle, face the last roller of the above guide roller with an appropriate interval, and place it on the machine frame with a predetermined interval. It is fixed horizontally. The folded film 12 is the plate body
At the hypotenuse parts 21-3 and 21-3 of 21,21, the sections are folded inward from the top and bottom to form a U-shaped cross section, and the direction is changed by 90 degrees so that the articles 2 to be packaged are fed in the same direction. become.

As shown in FIG. 1, the article-to-be-packaged supply 30 is arranged horizontally so that, for example, one end of the supply table 31 faces the opening of the opening 20, and the front end of the supply table 31 is provided. To the sealing portion of the L-shaped sealer 40, a conveyor belt 32 is provided.
32 is operated intermittently in synchronization with the operation of the L-shaped sealer 40. This packaged goods supply section
In addition to the supply table 31, a chain, a roll conveyor, a slide table, or the like can be used as the transfer means 30.

The L-shaped sealer 40 according to the present invention welds and seals two locations on the upstream and downstream sides of the film 12 parallel to each other with a cutting line therebetween and cuts the middle thereof with a part of a cutting blade. At the same time, the side edge opening end in the film flow direction is also welded in parallel at two positions on the left and right, with the cutting line interposed, and the middle thereof is cut by a part of the cutting blade.

Specifically, the L-type sealer 40 according to this embodiment
Has a pair of rectangular frames 41, 42 arranged vertically with the half-folded film 12 flipped at the film inversion opening 20 and moving horizontally. A substantially L-shaped seal bar 43 is attached to the two adjacent frame portions 41a of the upper frame body 41, and the two adjacent frame portions 42a of the lower frame body 42 facing the frame portion 41a are adjacent to each other. Similarly, an L-shaped seal pedestal 44 is attached. An air cylinder (not shown) is attached to the upper frame 41, and the cylinder is moved up and down at a predetermined timing and stroke. On the other hand, the lower frame 42 is attached to a machine frame (not shown) so that its installation height can be adjusted. The adjusting means for this purpose is performed, for example, by rotating an adjusting bolt via a bevel gear or the like.

As shown in FIGS. 2 and 3, the basic structure of the seal bar 43 is composed of a long metal seal bar body 43a containing a cartridge heater 43b. According to the illustrated example, the cross section of the seal bar main body 43a is substantially Π-shaped, and the lower end surface of the seal bar main body 43a forms two rows of seal surfaces 43a-1 and 43a-2. As shown in FIG. 6, the inner seal surface 43a-1 is continuously bent at a right angle, and the outer seal surface 43a-2 has one end extending linearly and the other end having a predetermined gap at the end thereof. Are arranged at right angles to each other. An elastic member 43c made of silicon rubber or the like having a rectangular cross section and having heat resistance is additionally attached and fixed to each side surface of each sealing surface 43a-1, 43a-2 of the seal bar body 43a. 7 and 8 are examples in which the inner and outer sealing surfaces 43a-1 and 43a-2 are in two rows, respectively.
In FIG. 7, each sealing surface 43a-1, 43a-2 is continuously double-sealed, and in the example of FIG.
Each of the two rows arranged in parallel with a-1, 43a-2 is staggered. As described above, in the present invention, the arrangement shape of the sealing surfaces 43a-1 and 43a-2 is appropriately changed depending on the article to be covered with the multilayer film.

On the other hand, the seal pedestal 44 is shown in FIGS.
As shown in Fig. 4, a prismatic columnar main body 44a having a slit-shaped opening 44b in the longitudinal direction of the upper surface, and the same columnar main body 44a.
And an elastic member 44c having a rectangular cross section made of the same material as the elastic member 43c divided into left and right so as to communicate with the opening 44b. The upper surface of this elastic material 44c is the sealing surface 43a-
The receiving surfaces 44c-1, 44c-2 for receiving 1,43a-2 are constructed. As described above, the seal pedestal 44 is installed so as to face the film traveling surface, and its installation height can be adjusted appropriately.

In the opening 44b, the cutting blade 45, which is the most characteristic feature of the present invention, is arranged along with the seal bar 43 and the seal receiving base 44 along the opening 44b. Figure 9
Shows the cutting blade structure of the corner portion of the L-shaped sealer 40 in the present embodiment, and as can be understood from the same figure and FIG. 6, the cutting blade 45 is joined in a substantially T shape at the corner portion in the present embodiment. It is integrated. As shown in FIGS. 2 and 9, the cutting blade 45 has a large number of sharp saw blade-shaped cutting edges 45a at predetermined intervals in the longitudinal direction, and the lower end of the cutting blade 45 supports the cutting blade. It is supported by the rod end of an air cylinder 47 fixed to a base 46 via a member 45b.
Therefore, a loose insertion hole 44d for loosely inserting the cutting blade support member 45b is formed on the lower surface of the seal receiving base 44, and a loose insertion hole for loosely inserting the rod of the air cylinder 47 is formed on the base 46. 46a is formed. Further, the seal receiving base 44
A guide rod 48 for guiding the up-and-down movement of the seal receiving base 44 is attached between the base and the base 46, and a spring 49 for constantly biasing the seal receiving base 44 upward is interposed. It should be noted that the base 46 also has adjusting means for adjusting the vertical height, like the seal receiving base 44.

FIGS. 3 to 5 show an operating procedure at the time of welding and cutting by the apparatus of the present invention constructed as described above. The opening of the bi-fold film 12 which is inverted by the film inversion opening 20 and moves horizontally. The next article 3 to be packaged, which is transferred from the article-to-be-packaged supply section 30, is accommodated in the section and reaches the L-shaped sealer 40 of the present invention. At this time, as shown in FIG. 3, the upper frame body 41 standing by above the lower frame body 42 is lowered by the operation of an air cylinder (not shown) to be in the state shown in FIG. That is, the seal surfaces 43a-1 and 43a-2 of the seal bar body 43a heated by the cartridge heater 43b simultaneously receive the upstream side opening and the side edge opening of the bi-fold film 12.
It is pressed against the receiving surfaces 44c-1 and 44c-2 of 44, and the polyethylene film is welded and sealed. Then, the air cylinder
47, the cutting blade 45 between the receiving surfaces 44c-1 and 44c-2 moves upward by a predetermined stroke as shown in FIG.
Cuts while piercing the middle of the half-folded film 12 stretched between the left and right sealing surfaces 43a-1, 43a-2 and the left and right receiving surfaces 44c-1, 44c-2.

According to this embodiment, since the multilayer film has a heat shrinkability, when the sealing surfaces 43a-1 and 43a-2 are welded, the sealing surfaces 43a-1 and 43a-2 are sealed. The part of the double-folded film 12 is also heated to some extent and heat-shrinks to be in a tensioned state. Therefore, the cutting edge of the cutting blade 45 is sharp.
At the same time as the 45a is pierced, the cut edge is enlarged, and the bi-fold film 12 is surely cut before the cutting blade 45 is fully raised.

Even if the multi-layer film does not have heat-shrinkability, the cutting structure of the present invention allows the cutting blade 45 to be completely lifted along the row of cutting edges by simply raising it. Can be done.

When this cutting is completed, the cutting blade 45 descends, its cutting edge 45a is immersed between the left and right receiving surfaces 44c-1 and 44c-2, and subsequently, the seal bar 43 together with the upper frame body 41 is shown in FIG. The packaging is completed by ascending to the standby position shown in. A package discharge unit 50 is disposed on the downstream side of the L-shaped sealer 40 as in the conventional case, and the package discharge unit 50 is generally a discharge belt conveyor 51.
Consists of. Although not shown, a heat tunnel is installed in the middle of the package discharge unit 50.

As described above, the packaging body 3-1 in which the film 12 is sealed and in the unshrinked state passes through a heat tunnel (not shown) in the middle of being transferred to the discharge belt conveyor 51 and discharged. The film 12 is heat shrunk,
It comes into close contact with the entire surface of the article to be packaged 3. At this time, the air present in the film passes through the point-shaped non-sealing portions present at the corners of the L-shaped sealer 40 to the outside, so that there is no hindrance to the shrinkage of the film 12. Further, at the time of this heat shrinkage, the non-sealed portion is completely tightly sealed by the shrinkage of the film, and the package after the heat shrinkage is completely sealed by the film 12.

The above is an example in which the present invention is applied to a double-fold film packaging machine, but the packaging form of the present invention is not limited to the above-mentioned packaging machine. Without hanging from the film roll through a guide roller, etc., put the article to be packaged into the half-folded film from the part opened by appropriate means, pull out the film by the weight of the article, and weld and cut with the L-type sealer It can also be applied to the vertical wrapping machine of the
While inserting both side edges of the film under the transfer belt along the upper surface of the closing piece, in this state, it can be used for any automatic packaging machine such as a method of pulling out the leading edge of the film from the front edge of the former until it goes through the sealing device. It is possible to apply. Of course, the manufacturing method of the present invention can be applied to shrink-wrapping by manual work.

[0030]

As is apparent from the above description, according to the welding and cutting apparatus for multi-layered films of the present invention, a multi-layered film made of a material having special characteristics having a remarkable difference in welding temperature can be used. Also, in order to simultaneously weld the front and rear welded portions by a single device, and to cut the middle of the welded portions by a cutting blade having a saw-toothed blade tip that operates independently from the heating seal bar, The seal bar ensures the sealing of the front and rear welded seals, and at the same time, without cutting the cutting blade in an overheated state, the intermediate cutting portion is simply pressed by the cutting blade to surely and without melting the film. Can be cut efficiently.
Moreover, the welding and cutting apparatus of the present invention does not become so complicated in structure as compared with the conventional apparatus, and the process is remarkably simplified, which is economically useful.

[Brief description of drawings]

FIG. 1 is a schematic perspective view of a double-folded film automatic packaging machine to which the present invention is applied.

FIG. 2 is an enlarged perspective view of a main part of the multilayer heat-welding synthetic resin multilayer film welding / cutting device of the present invention, which is partially cut away.

FIG. 3 is a cross-sectional view of an essential part showing the configuration of the welding cutting device.

FIG. 4 is a cross-sectional view of essential parts showing a state during welding by the same device.

FIG. 5 is a cross-sectional view of essential parts showing a state during welding / cutting by the same device.

FIG. 6 is a plan view of relevant parts showing a configuration of a seal bar at a corner of an L-shaped sealer that is a typical embodiment of the present invention.

FIG. 7 is a partial plan view showing an example of a seal pattern according to the device of the present invention.

FIG. 8 is a partial plan view showing another example of the seal pattern.

FIG. 9 is a perspective view of essential parts showing a configuration of a cutting blade at a corner portion of an L-shaped sealer that is a typical embodiment of the present invention.

[Explanation of symbols]

 1 Automatic double-wrapping film wrapping machine 3 Packaged goods 3-1 Package 10 Film supply section 11 Roll film 12 (Folded) film 13 Support roller 14 Guide roller 20 Film reversing opening 21 Plate 21-1-21-2 (Side the right angle) Two sides 21-3 Oblique side part 30 Article supply part 31 Supply table 32 Conveyor belt 40 L type sealer 41 Upper frame 41a, 41b Frame 42 Lower frame 43 Seal bar 43a Seal bar main body 43a-1 , 43a-2 Sealing surface 43b Cartridge heater 43c Elastic material 44 Seal receiving base 44a Columnar body 44b (Slit-like) opening 44c Elastic material 44c-1,44c-2 Receptive surface 44d Free insertion hole 45 Cutting blade 45a Cutting edge 46 Base 47 Air cylinder 48 Guide rod 49 Spring 50 Package discharge section 51 Discharge belt conveyor

Claims (5)

[Claims] 1. A heating seal bar and a seal cradle are provided,
Upper and lower parts 2 that accommodate articles to be packaged and are supplied intermittently
A welding cutting device for a multilayer film, which sequentially cuts and welds a plurality of multilayer films at the same time, wherein the seal pedestal has a void portion sandwiching a cutting line of the multilayer film, and each seal receiving surface is of the film. A cutting blade that is installed facing the traveling surface and that moves into and out of the receiving surface to a position above the receiving surface by the first actuating means is provided, and the blade portions of the cutting blade have sharp blade edges arranged at equal intervals. The seal bar has a concave groove for receiving the cutting edge of the cutting blade in the center of the width of the seal surface, and each seal surface is disposed so as to face each of the receiving surfaces. And further comprising second operating means for moving up and down between the receiving surface pressing position and the upper standby position, and after the second operating means operates and the sealing surface presses each receiving surface, The first actuating means actuates and the upper limit of the cutting blade An apparatus for welding and cutting a multilayer film, comprising a timing control means for raising the position to a position. 2. The welding cutting device according to claim 1, wherein the multilayer film comprises two or more synthetic resin film layers having different welding performances. 3. The welding cutting device according to claim 1, wherein the multilayer film comprises a metal film and one or more synthetic resin film layers. 4. The upper and lower films around two of the articles to be packaged, which are sequentially housed in the multilayer film, in which the seal bar and the cutting blade are substantially L-shaped and are folded in two and transferred intermittently. The multi-layer film welding and cutting apparatus according to claim 1, wherein the welding and cutting are performed at the same time. 5. The fusion cutting welding device for a multilayer film according to claim 1, wherein each of the receiving surfaces is made of an elastic material made of a heat resistant rubber material or the like.